Not answering your question directly, but the homeless crisis in the US seems to have hit the radar in the early 1980s.
Part of that may be changing terminology -- earlier use of "homeless" tends to focus on "people made homeless" (or "... left ...") after some calamity: structure fire, flood, hurricane, etc. In the 1980s "homeless" became a chronic condition. Other terms may have existed for the long-term unhoused. I'm not aware of them.
What specifically changed, I'm not certain, though circumstances leading to the role of real estate as an asset rather than a utility may be part of that.
They're arguing for the removal of regulations in a general sense, not just specific problematic regulations. The solution being proposed is incorrect, regardless of whether the problem has been correctly identified.
This particular market failure is definitely caused by government.